JPH09258827A - Unmanned guiding vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent collision even when a traveling speed and a steering angle are changed during traveling by operating a braking device by the lower detection sensitivity of a receiver as the steering angle of the steering wheel of a vehicle main body becomes larger. SOLUTION: When the vehicle main body starts a traveling operation, the receiver 21 detects a distance with a guiding vehicle in front by the level (s) of signals. Then, an angle to which the steering wheel is turned is detected by a steering angle detection means 17 and a set reception level S at which the braking device 10 starts an operation is set based on the size of the angle. Then, the reception signal level (s) is compared with the set reception level S at which the braking device 10 starts the operation, and when it is reached, the braking device 10 is operated and shifted to a stop operation. In such a manner, since control is performed so as to operate the braking device 10 even when the reception level of the receiver 21 is low as the steering angle is larger, even when the vehicle traveling in front is present right around a corner, this unmanned guiding vehicle is stopped in front of the corner and safety is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unmanned guided vehicle equipped with a collision preventing device for preventing a collision from a vehicle traveling in front of the vehicle, which is judged from the reception level of electromagnetic waves oscillated from another vehicle existing in the traveling direction. Regarding

[0002]

2. Description of the Related Art Conventionally, this type of unmanned guided vehicle has been known as a real car.
As disclosed in Japanese Patent Publication No. 7-18197 (B60R21 / 00), a sensor that emits ultrasonic waves is attached to the front surface of the vehicle body, the reflection time of the ultrasonic waves emitted is detected, the distance to an obstacle is detected, and stop is required. It is known to stop the vehicle when the distance is reached. At the time of this stop, in order to change the stop distance depending on the type of obstacle, for example, the person and the vehicle, the rear part of the vehicle is inclined with respect to the front-rear direction, and even if they are equidistant, the ultrasonic waves The type of obstacle in front was discriminated by changing the reflection time.

However, with the above-mentioned structure, the vehicle body is set so as to stop at a predetermined distance. Therefore, the braking distance increases as the speed increases, and a collision may occur if the speed is too high. It was dangerous because it came.

Further, in the above-mentioned unmanned guided vehicle, the types of obstacles between the person and the vehicle body are only discriminated from each other, and the stop distances are made different. For example, as shown in FIG. When the vehicle main body 92 is traveling in the direction of the arrow and another vehicle 93 is stopped immediately after turning the curve, the so-called stop vehicle 93 from the so-called curved place (the vehicle main body shown by the broken line in the figure) If the distance exceeds the braking distance, the vehicle body 92 is within the braking distance range of the vehicle body 92 when the obstacle sensor 94 detects the preceding stopped vehicle 93.
There is a problem that the vehicle body 92 cannot stop and collides with the previously stopped vehicle 93. The problem is that the smaller the curve radius, the greater the possibility of suddenly detecting an obstacle, and thus the braking distance from detection to stop becomes insufficient. As a countermeasure for this, a method of increasing the set reception level at which the braking device starts operating from the beginning can be considered, but in this case, it is not possible to stop at the optimum distance, or noise is picked up and mistakenly made. It may stop or cause inconvenience in traveling operation.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and it is an object of the present invention to provide a safe unmanned guided vehicle which prevents a collision even when the traveling speed or the steering angle changes during traveling. To do.

[0006]

According to a first aspect of the present invention, there is provided a receiver for detecting an electromagnetic wave from another vehicle existing on the running direction side of a vehicle body running on a laid track, and the receiver. An unmanned guided vehicle including a braking device that stops the vehicle body based on the detection sensitivity of a detector, which is provided with steering angle detection means for detecting a steering angle of a steered wheel of the vehicle body. A control circuit for operating the braking device with a small detection sensitivity of the device is provided.

The vehicle body traveling on the track travels while detecting the reception sensitivity of the electromagnetic waves oscillated from the preceding vehicle existing on the traveling direction side. When the detection sensitivity reaches a predetermined level, that is, when the distance to the preceding vehicle reaches a predetermined distance, the braking device is operated and stopped. At this time, the steering angle of the steered wheels is detected, and the braking device is controlled to operate with a smaller detection sensitivity in a place where the steering angle is larger. That is, the control is performed such that the smaller the radius of the curve is, the longer the stopping operation is performed.

According to a second aspect of the invention, a receiver for detecting an electromagnetic wave from another vehicle existing on the running direction side of the vehicle body running on the laid track, and a vehicle based on the detection sensitivity of the receiver An unmanned guided vehicle including a braking device for stopping a main body, wherein speed detecting means for detecting a traveling speed of the vehicle main body is provided, and the braking device operates with a smaller detection sensitivity of the receiver as the traveling speed increases. A control circuit is provided.

The vehicle body traveling on the track travels while detecting the reception sensitivity of the electromagnetic waves oscillated from the vehicle traveling in the forward direction existing in the traveling direction. When the detection sensitivity reaches a predetermined level, that is, when the distance to the preceding vehicle reaches a predetermined distance, the braking device is operated and stopped. At this time, the traveling speed of the vehicle body is detected, and the braking device is controlled to operate with a smaller detection sensitivity as the speed increases. That is, the control is performed such that the higher the traveling speed, the longer the stopping operation.

Further, according to the third aspect of the invention, a receiver for detecting an electromagnetic wave from another vehicle existing on the running direction side of the vehicle body running on the laid track, and a vehicle based on the detection sensitivity of the receiver An unmanned guided vehicle including a braking device for stopping a main body, wherein steering angle detection means for detecting a steering angle of steered wheels of the vehicle main body, and speed detection means for detecting a traveling speed of the vehicle main body are provided, It is characterized in that a control circuit is provided for changing the sensitivity of the receiver for operating the braking device, based on signals of both the steering angle and the traveling speed.

The vehicle main body running on the track runs a forward running vehicle existing on the running direction side while detecting the reception sensitivity of electromagnetic waves oscillated from the vehicle. When the detection sensitivity reaches a predetermined level, that is, when the distance to the preceding vehicle reaches a predetermined distance, the braking device is operated and stopped. At this time, the steering angle and the traveling speed of the steered wheels are detected, and the braking device is controlled to operate with a smaller sensitivity when the steering angle is larger, and with a smaller sensitivity when the traveling speed at that time is higher. That is, the control is performed such that the smaller the curve radius is, the longer the distance is stopped, and the faster the speed is, the longer the distance is stopped.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First, a block diagram of the control circuit will be described with reference to FIG.

Reference numeral 1 is a motor for driving a vehicle body 2 which is an unmanned guided vehicle. The motor 1 is driven by a battery 3 as a power source. The battery 3 includes, for example, a 24-volt lead-acid battery.

Reference numeral 4 is a flywheel diode connected in parallel to the motor 1 and is provided for PWM control.

Reference numeral 5 is a constant voltage circuit for stepping down the voltage of the battery 3 and supplying electric power to the control circuit, that is, the microcomputer 6. The constant voltage circuit 5 outputs the starting voltage of the microcomputer 6, for example, 5 volts. To do.

Reference numeral 7 is a drive circuit for PWM-controlling the motor 1, and the drive circuit 7 sends a PWM signal to a switching element 8 connected in series with the motor 1 to turn the switching element 8 ON / OFF. It is designed to drive 1.

Reference numeral 9 denotes a speed detecting circuit for detecting the number of rotations of wheels (not shown) of the vehicle body 2. The speed detecting circuit 9 is composed of, for example, an encoder, and the detected speed signal is a microcomputer. 6 is input.

Reference numeral 10 is a braking device such as an electromagnetic brake that stops the rotation of the wheels, and the braking device 10 operates based on a braking signal from the microcomputer 6 via a braking drive circuit 11. Then, deceleration and stop operations are performed.

Reference numeral 12 is a guide wire buried along a predetermined traveling path, and the guiding wire 12 connects the traveling paths with one line, and a magnetic field is generated by passing an electric current through this.

A pickup coil 13 is provided so as to move in association with the steered wheels of the vehicle body 2 and detects the magnetic field from the guide wire 12. The pickup coil 13 is a guide wire 12.
On the other hand, the vehicle body 2 is provided in a pair on the left and right, and the vehicle body 2 travels while detecting the magnetic field from the guide wire 12. In addition, the pickup up coil 13 has an amplifier circuit.
14 is provided, and the amplified signal is input to the microcomputer 6, and by inputting the signal, it is possible to determine how much the steering wheel is deviated to the left or right with respect to the guide wire 12.

Reference numeral 15 is a steering motor for moving the steered wheels to the left and right. The steering motor 15 moves the steered wheels to the left and right in order to travel along the guide line 12 based on the input of the pickup coil 13. The microcomputer 6 determines how much to move and outputs a signal to the steering motor drive circuit 16 to move the steering motor 15.

Reference numeral 17 denotes a rudder angle detecting means for detecting how many times the steered wheels are bent in the straight traveling direction.
The 17 is designed to detect the steering angle by changing the resistance value of a potentiometer attached to the steered wheels.

Reference numeral 18 denotes a magnet detection circuit for detecting the magnetic field of a magnet embedded near the guide wire 12 on the road surface. Speed control is performed by embedding the S pole and N pole of the magnet in the road surface.
For example, commands such as deceleration, acceleration, and stop can be given to the vehicle main body 2, and if the vehicle always passes through the place, the operation of the command is performed. The magnet can also give a command to attenuate the reception sensitivity of the obstacle sensor 19, which will be described later, that is, it can also give a command not to stop unless the distance between the obstacle sensor and the obstacle becomes half the normal value.

Reference numeral 19 is an obstacle sensor for detecting an obstacle ahead in the traveling direction. The obstacle sensor 19 oscillates an ultrasonic wave and detects the strength of the reflected ultrasonic wave or the reflection time to obstruct the obstacle. The distance to the object is detected, and when the microcomputer 6 inputs this signal to reach a dangerous distance that must be stopped, the braking device 10 is operated by the signal output from the microcomputer 6, and the vehicle body is at a safe distance. 2 is controlled to be stopped.

Reference numeral 20 denotes a transmitter which is provided at the rear of the vehicle body 2 and constantly transmits radio waves toward the rear. Reference numeral 21 denotes a receiver which is provided in front of the vehicle body 2 and receives radio waves from the vehicle body in front. The receiver 21 determines by the microcomputer 6 when the radio wave transmitted from the vehicle body traveling in front is received at a predetermined level or higher, that is, when the distance from the vehicle body traveling in front reaches a predetermined distance. The braking device 10 is operated to stop.

Reference numeral 22 denotes the obstacle sensor 10 and the receiver 21.
By the buzzer, the buzzer 22 informs the user when the distance from the obstacle or the vehicle body ahead is within the range where the vehicle must stop.The buzzer 22 informs the user that this is detected. It has become.

The receiver 21 and the receiver of the obstacle sensor 19 are provided with a volume adjusting sensitivity, which is used at the time of factory shipment to finely adjust the stop distance. For example, the buzzer is installed by installing the vehicle main body 2 and the transmitter or the pseudo obstacle at a distance that must be stopped, and adjusting the sensitivity adjustment volume of the obstacle sensor 19.
The stop distance can be set to a predetermined sensitivity by ringing 22 and fixing the volume at the position where the ringing starts.

Reference numeral 24 is a remote control signal input means for inputting a remote control signal from a remote control transmitter possessed by the user, and the remote control signal input means 24 can receive a start / stop instruction signal from the remote control transmitter. . The remote control signal input means 24 inputs the received signal to the microcomputer 6 to start and stop it.

Next, the first embodiment will be described with reference to FIGS.

When the vehicle body 2 starts a traveling operation (S
1), the receiver 21 detects the distance from the guided vehicle ahead by the signal level s (S2). Then, the steering angle detecting means 17 detects the angle at which the steered wheels are facing (S3), and the braking device is based on the set value shown in FIG. 2 according to the magnitude of the angle.
Set the reception level S at which 10 starts to operate (S
4). Then, the reception signal level s is compared with the set reception level S at which the braking device 10 starts to operate (S5), and if not reached, this is repeated from S2. If it is reached, the braking device 10 is operated and the stopping operation is started (S6).

As described above, as shown in FIG. 2, the larger the steering angle, the more the control is performed so that the braking device is operated even if the reception level of the receiver 21 is small, that is, the larger the steering angle, the more the braking device is operated. Since the distance from the running vehicle is increased, the unmanned guided vehicle can be stopped before turning even if there is a preceding vehicle immediately after turning at a corner, and safety can be improved.

Next, a second embodiment will be described with reference to FIGS.

In this embodiment, the distance from the preceding vehicle for operating the braking device is set according to the steering angle in the first embodiment, and the speed signal from the speed detection circuit 9 is changed in accordance with the speed signal. The set values shown in FIG. 6 are set, and the values are set accordingly.

This will be described with reference to the flowchart of FIG.

When the traveling operation is started (S1), the receiver 21 detects the distance from the guided vehicle ahead by the signal level s (S).
2). Then, the traveling speed is detected by the speed detection circuit 9 (S3), and the set reception level S at which the braking device 10 starts to operate based on the set value shown in FIG.
Is set (S4). Then, the reception signal level s is compared with the set reception level S at which the braking device 10 starts to operate (S
5) If not reached, repeat from S2. If it is reached, the braking device 10 is operated and the stopping operation is started (S6).

In this way, as shown in FIG. 6, the higher the traveling speed is, the more the receiving level of the receiver 21 is reduced. Therefore, the braking device is controlled to operate, that is, the faster the traveling speed is, the more the braking device is operated. Since the distance to the preceding vehicle is increased, the vehicle can be stopped without hitting the vehicle even if the speed is increased and the braking distance is extended, and safety is improved.

Next, a third embodiment will be described with reference to FIGS. 7 and 8.

In this embodiment, the combined control of the first embodiment and the second embodiment is performed, and the set reception level of the receiver 21 is set to the distance for operating the braking device according to the steering angle. At the same time, the set value is changed depending on the traveling speed at that time.

When the traveling operation is started (S1), the receiver 21 detects the distance from the guided vehicle ahead by the signal level s (S).
2). Then, the steering angle detecting means 17 detects the angle of the steered wheels (S3), and further detects the traveling speed at this time (S4). According to the angle and speed, the set reception level S of the receiver 21 when the braking device 10 operates is set based on FIG. 8 (S5). Then, the received signal level s and the operation level S of the braking device 10 are compared (S6), and if not reached, the process is repeated from S2. If it is reached again, the braking device
10 is operated and the operation moves to the stop operation (S7).

As described above, based on the detected values of both the steering angle of the first embodiment and the traveling speed of the second embodiment, the distance from the vehicle body in front of which the braking device operates, that is, the receiver 21. Since the setting reception level S of is changed, the stop distance can be changed according to the size of the turning angle and the traveling speed, so that the safety is improved.

In the embodiment of the present invention, the drive source is a motor. However, if the vehicle is an induction vehicle, the drive source is irrelevant and an engine may be used.

Further, in the present embodiment, the stop distance is changed by changing the sensitivity of the receiver 21 based on the steering angle of the steered wheels, the traveling speed, or both signals. Control may be performed so as to detect an uphill and change the reception sensitivity. In this case, in the case of a downhill, the set reception level at which the braking device starts operating is reduced to increase the braking distance, and in the case of an uphill, the set reception level at which the braking device starts operating is increased to perform braking. Shorten the distance.

Further, in the present embodiment, as shown in FIGS. 2, 6 and 8, the set reception level at which the braking device of the receiver 21 starts to operate is set so as to be linearly changed. A value may be set and the value may be digitally changed.

Further, in this embodiment, the set reception level of the receiver 21 is changed according to the steering angle and the traveling speed, but the obstacle sensor 19 is also the same. In that case,
In particular, it is necessary to remove trees that obstruct the curve, etc.

[0046]

According to claim 1 of the present invention, the larger the steering angle, the more the control is performed so that the braking device operates even if the reception level of the receiver is small, that is, the larger the steering angle, the more the braking device operates. Since the distance to the running vehicle is increased, the vehicle body can be stopped before turning even if there is an obstacle immediately after turning at a corner, and safety can be improved.

According to a second aspect of the present invention, the vehicle is controlled so that the braking device operates even if the reception level of the receiver decreases as the traveling speed increases, that is, as the traveling speed increases, the front running vehicle operates the braking device. Since the distance between and is increased, even if the speed is increased and the braking distance is increased, the vehicle can be stopped without hitting the vehicle and the safety is improved.

Further, according to claim 3, the distance to the vehicle in front of which the braking device operates, that is, the reception level of the receiver is changed based on the detected values of both the steering angle and the traveling speed. Since the stop distance can be changed according to the size of the turning angle and the traveling speed, safety is improved.

[Brief description of drawings]

FIG. 1 is a flowchart of a control circuit of an unmanned guided vehicle that is a first embodiment of the present invention.

FIG. 2 is a graph showing a set reception level of the receiver with respect to the same steering angle.

FIG. 3 is a schematic view showing the traveling state.

FIG. 4 is a block diagram of the control circuit.

FIG. 5 is a flowchart of a control circuit for an unmanned guided vehicle according to a second embodiment of the present invention.

FIG. 6 is a graph showing a set reception level of the receiver with respect to the same traveling speed.

FIG. 7 is a flowchart of a control circuit for an unmanned guided vehicle according to a third embodiment of the present invention.

FIG. 8 is a graph showing a set reception level of the receiver with respect to the steering angle and the traveling speed.

FIG. 9 is a schematic diagram showing a traveling state of a conventional unmanned guided vehicle.

[Explanation of symbols]

 21 receiver 10 braking device 17 rudder angle detection means 6 control circuit 9 speed detection means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naohiro Shigeta 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (3)

[Claims] 1. A receiver for detecting an electromagnetic wave from another vehicle existing on the running direction side of a vehicle body running on a laid track, and a braking device for stopping the vehicle body based on the detection sensitivity of the receiver. An unmanned guided vehicle comprising: a steering angle detecting means for detecting a steering angle of a steering wheel of the vehicle body,
An unmanned guided vehicle comprising a control circuit for operating a braking device with a smaller detection sensitivity of the receiver as the steering angle is larger. 2. A receiver for detecting an electromagnetic wave from another vehicle existing on the running direction side of a vehicle body traveling on a laid track, and a braking device for stopping the vehicle body based on the detection sensitivity of the receiver. An unmanned guided vehicle equipped with a speed detection means for detecting a traveling speed of the vehicle body, and a control circuit for operating a braking device with a smaller detection sensitivity of the receiver as the traveling speed becomes faster. A featured unmanned guided vehicle. 3. A receiver for detecting an electromagnetic wave from another vehicle existing on the running direction side of a vehicle body running on a laid track, and a braking device for stopping the vehicle body based on the detection sensitivity of the receiver. An unmanned guided vehicle comprising: a steering angle detecting means for detecting a steering angle of steered wheels of the vehicle body; and a speed detecting means for detecting a traveling speed of the vehicle body, wherein both the steering angle and the traveling speed are provided. An unmanned guided vehicle is provided with a control circuit that changes the detection sensitivity of a receiver that operates the braking device based on the signal of.